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Finding the Fourth Proportional to 621.80, 930.87 and 415.86

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Solution

The fourth proportional to 621.80, 930.87 and 415.86 is: 622.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.80 : 930.87 = 415.86 : x
  2. Step 2: Convert to fraction form
    621.80/930.87 = 415.86/x
  3. Step 3: Cross multiply
    621.80x = 930.87 × 415.86
  4. Step 4: Simplify right side
    621.80x = 387,111.60
  5. Step 5: Solve for x
    x = 387,111.60/621.80
  6. Step 6: Final answer
    x = 622.57

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.